International large-scale education assessments (ILSAs) are used to compare the performance of countries' educational systems, but these rankings can be misleading and should not be the sole determinant informing educational policy, Judith Singer and Henry Braun caution in this Policy Forum. They note that, because of overlapping margins of error, there may not be any statistical difference between the ranked average performances of many countries. Furthermore, ILSA rankings may not reflect education-system features so much as they reflect broader cultural attitudes and behaviors that impact ILSA performance. The authors write that, despite discrepancies in data and cross-cultural equivalence challenges, some aspects of ILSAs could be harnessed, in combination with within-country analyses, to pinpoint deficits in educational systems and find solutions. One such case is by looking at the strength of the relationship between socioeconomic status and school performance; for instance, the relationship between scores and socioeconomic status is noticeably weaker in Canada than in the United States. Looking into patterns such as this may prompt countries with less equitable systems to experiment with strategies their neighbors have used to improve educational equity, Singer and Braun say. They conclude by outlining five suggestions for improved use of ILSA data, including linking ILSA data to other data sources and using findings from ILSA analyses to stimulate randomized field trials that test the effects of specific interventions.